I always carry my cameras across my body - on the chest they sway and swing uncontrollably (often into things)!
I buy old, well-worn wide canvas straps from the 1970s with all-metal fittings (no plastic!), including quick-release clips. I bleach these, then dye them (olive green - ‘cos I like the colour, and it’s discrete).
What I want from a strap (strong and reliable taken as givens):
• Comfortable - hence worn and soft, and wide for weight spreading.
• Slippery - worn across the body means it needs to slide, so musn’t be grippy, and no “shoulder pad” thing.
• Cheap - usually about $1!
I usually bleach and dye a handful every few years as friends and colleagues like them too, saying they’ve real character, so I’m always giving them away!
Pic of the strap I’ve used for a decade now (with my Frankenstein 1 kg (2 lb) 55-110 mm shift zoom lens!).